Precious stone



FIG. 1 is a bottom view, showing my new design;

FIG. 2 is a right view thereof;

FIG. 3 is a left view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a rear thereof; and,

FIG. 6 is a front thereof. 

The ornamental design for a precious stone, as shown. 